The Fire Service was called to put out couch fires at 5.50pm, 6.05pm and 6.30pm at a "large block party" on Castle St, Willowbank senior station officer Rob Torrance said.
"The crowd were good-natured but it does tie up our resources as we are a rescue pump, and may be called to an accident on the Northern Motorway at any time."
The couches were mostly made of polyurethane, and fighting a couch fire was equivalent to dealing with 25 litres of petrol, requiring a high-pressure hose to extinguish, he said.
The Willowbank crew was called to two further Castle St fires shortly after 9pm, and another couch fire at 10pm.
Senior Sergeant Craig Brown said the party attracted hundreds of largely good-natured revellers, many of whom were in costumes, with police making three arrests.
Police arrested two 20-year-old female University of Otago students for disorderly behaviour, one of whom for climbing on top of a fire appliance.
A 21-year-old University of Canterbury student was also arrested for disorderly behaviour after damaging a car, Snr Sgt Brown said.
The trio were likely to appear in the Dunedin District Court next week.
